Check this out! DUAL Carbs

[SteelyDel]

https://portland.craigslist.org/mlt/pts/5515590070.html

 

I've never seen this set up before!

[turbosubarubrat]

https://portland.craigslist.org/yam/cto/5487094583.html

[griffo]

https://portland.craigslist.org/mlt/pts/5515590070.html

 

I've never seen this set up before!

 

Looks like the generic setup for a GSR or GFT (Hitachi DCG306) engine  

[spicypeanut]

Wonder how this would do in my brat. Any increase in performance over a weber?

[TOONGA]

Wonder how this would do in my brat. Any increase in performance over a weber?

It would not fit as the 1600 manifold is shorter than the 1800 manifold, I found out the hard way .

 

Unless you have a 1600 in your brat that is.

 

TOONGA

Edited April 4, 2016 by TOONGA

[spicypeanut]

My Brat is a 78 so it has the 1600

 

So I wonder, could I run dual weber carbs?

[SmashedPeaches]

These came off the now rare EA71S engine. We got a bunch in the states in brats, but they are long gone these days. That manifold will bolt to your normal EA71 manifold but without much power increase, as the dual carb setup was paired with different EA71 heads and a sportier cam profile. You could still run it however for the novelty.

[waimaks]

I have dual carbs on my regular EA71 in my GSR.

I don't have any figures but it gave it a bit more go and opened up another 500/1000rpm perhaps.

 

[Loyale 2.7 Turbo]

... That manifold will bolt to your normal EA71 manifold but ... was paired with different EA71 heads and a sportier cam profile ...

 

Yes, the EA71S featured sportier cam with Reversed Valves, exhaust / intake on the opposite positions. Without that, dual carbs will not add much to a Regular EA71.

 

My Brat is a 78 so it has the 1600  

So I wonder, could I run dual weber carbs?

 

Yes, with dual adapter plates and the related mess... 

 

Kind Regards.

Edited April 11, 2016 by Loyale 2.7 Turbo

[Leeroy]

 

Yes, the EA71S featured sportier cam with Reversed Valves, exhaust / intake on the opposite positions. Without that, dual carbs will not add much to a Regular EA71.

 

 

Different camshaft yes but no EA71 available to the public had reversed valves (unlike the EA63 and EA81S engines). 

[old sub freak]

I still have duel carbs on my 83 brat.I think it had a lot of jump when they were running good... And add in the cool factor and it really purrs.haha i have been thinking of replacing them with a weber.I have had the rig for 20 + years and rebuilt one carb 10?years ago haha .Smart ,I know,Don't even remember which one... haha. Anyway,from what I could dig up on the Hitachi carbs is that rebiult ones don't last and a new one is 800 bucks...... I would love to keep the duels on it but they have lost a lot of pep over the years. I thought of getting a couple of aftermarket ones off ebay and see what happens..I know they had more power than a single. We would have to race to see if the weber beats though.  ..Anyone ever hear any good about rebuilt Hitachi's? Todd

[Loyale 2.7 Turbo]

Why don't you try to run Twin Webers? 

[old sub freak]

Wouldn't fit .I tried... You would have to make or find  2 small stacks and linkage like a old VW had.. That worked for there 1800's 

[jono]

twin 32/36  Webers would be overkill, or maybe they would only both work in the primary circuit

 

As for twin Hitachis on a std engine, just the sound of twins is awesome - made mine sound like a ...an old VW Kombi two litre

 

Opened up the low down torque, mid range and upper rev range of power available, whatever power an EA81 can unleash.

My fuel economy remained good - mid 8 litres per 100 km. This was on my rebuild kitted and engine only 20,000km old 16/56 cam

I had to keep an eye on things on the highway as speeds would creep up, 110kph zone where most would do 120, some 130 almost, this thing was creeping up to 140 all on its own and more go underfoot all up long inclines.

 

I would be tempted to try the twins on a carb EA82 given EA82 has the valve configuration of EA81S

 

I reckon it is time someone tried to copy a Safari style set up, ambidextrous inlet adaptor to take a weber each side directly over the intake, channel coolant from side to side, long linkage for precise twin control.

Edited May 8, 2016 by jono

[griffo]

I have dual carbs on my regular EA71 in my GSR.

I don't have any figures but it gave it a bit more go and opened up another 500/1000rpm perhaps.

 

 

Imho, if you are looking for an easy upgrade beyond the 'GSR' twin DCG306 setup, then the Weber 40DCN running east-west over a modified single carb manifold is probably the best option. If you want to go beyond that with dual carbs mounted directly on top then you may get more top end BHP but I think the later engines with outside positioned intake valves and siamised exhaust ports probably limit this.

 

I did run a Weber 45 DCOE on my GSR at one point with a couple of custom tube elbows that bolted onto the existing carb flanges which did provide increased top end... adding another 5mph to the ultimate top speed. A 40DCOE might have been a more appropriately sized option as we had to run fairly small chokes from memory. Had to feed the throttle in gently at low revs but once it his 4000 it revved out like a rotary... fine on the track, but a bit tiresome on the road.

 

So my main take out is that even the dual DCG306 under-carburates the old EA63S gives v.good all round performance, although one thing the Weber did is cure the fuel surge in right-handers on the track. The DCN setup would do the same.